Power Calculation in Performance Engineering Techniques for Energy Consumption

In the following formula, `P_g` refers to the power consumption of the GPU, while `g` refers to the number of memory sticks (whose power consumption is defined as `P_r`):
https://github.com/Green-Software-Foundation/sci-guide/blob/5f63d846838fbbeff858c51afb234126d781ef81/docs/E/PerformanceEngineeringBased.md?plain=1#L17-L23

These two (seemingly unrelated) numbers get multiplied in the formula. Is this correct or am I getting something wrong?
I'd have expected the number of memory sticks to be defined as `r` with the formula being:

$P[kWh]=(c∙P_c+P_g+r*P_r)/1000$

Best regards